I was out tonight and noticed the rear tail pipe was glowing red. Took the jets out and noticed the front is a 152 and rear is 158, is this bigger than stock?

What are you guys running?

 

On what quad? A V?

 

Do you have the Icm computer in your Kawi? I put the ICM on my 750 Brute and it changes the timing, making it run much more hot then stock. Header pipes do glow now

 

Sorry guys, BF 750, and it is completely stock.

I cant figure it out, why it would do it with such a big jet?

 

They run the rear cylinder a little fatter because it gets hotter. Not as much airflow across it, and the air is already heated from the front cylinder. Just like on triple 2 strokes, they run the middle a little fatter. (Refering to the jet sizes here.)

 

Oh yea, check for air leaks between the carb and rear cylinder. Sounds like your running lean. Make sure your rear carb doesn't have any $hit stuck in it.

 

If you have taken your carbs off check your carb boots. I had mine jetted, and the boots got ripped when they put them back on. Whenever i hit water it would cut out and we finally found out what it was. They have had a few of them do that so if you have messed with teh carbs at all check the boots, that might be your lean mixure.

 

I pulled the carbs apart and cleaned them real good, checked the boots, no tears. It sounds like it is just running lean because of the jetting, but why with such a big jet?

 

See my first reply for the short, simple answer to that one.

 

Wow, This is a real mystery. Your jet spread is about right too. Might double check the boot again. Other than that I have no idea. Let us know what you find.